The present invention belongs to a class of mounting clips that are useful in the construction of buildings, particularly commercial buildings where a non-load bearing, exterior curtain wall is connected to the load bearing elements of a building and the curtain wall needs to be able to move with respect to the load bearing elements.
It is often advantageous to attach curtain walls systems to the load bearing elements of a building with connectors that permit a degree of relative movement between the wall system and other components of the building. There are many reasons for this. For example there can be extreme differences in temperature between the exterior curtain walls and the interior load bearing systems, and because the exterior curtain wall and the load bearing system often have different coefficients of expansion based on their different materials, under extreme temperature differences the curtain wall wants to shift with respect to the load bearing system. Exterior walls of buildings are also subject to deflection from wind and seismic forces. Furthermore, curtain walls are typically not designed to support vertical loads and must therefore by isolated from deflection of the primary load-bearing support structure of the building due to changes in live or dead loads carried by that structure. Providing a degree of freedom of movement within the wall and between the wall and the other components of a building can reduce stress and prevent fracture of connected parts due to the loading of the building, seismic and wind events or differences in the temperatures of the curtain wall and the load bearing elements.
A number of slide, or slip clips that permit relative movement between structural members have been patented.
U.S. Pat. No. 5,467,566, issued in 1995 to Allan J. Swartz and Gregory A. Kulpa teaches a slide clip where a fastener having a washer or spacer is connected to the supported member, and the slide clip is attached to the supporting member and to the fastener with the washer in such a manner that the slide clip can move with respect to the supported member. To allow relative movement between the fastener and the slide clip, Swartz and Kulpa taught that the spacer or washer on the fastener should be received in slots in the portion of the slide clip lying against the supported member and the spacer or washer should be thicker than the receiving portion of the slide clip. Planar flaps or extensions which were part of the washer or spacer and disposed parallel to the receiving portion of the slide clip extend over the receiving portion of the slide clip and prevent it from pulling away.
U.S. Pat. No. 5,876,006, issued in 1999 to Terry L. Sharp and Richard C. Eldenburg also teaches a slide clip where a spacer or fixed bracket is connected to the supported member and a slide clip is attached to the supporting member and the fixed bracket in such a manner that the slide clip can move with respect to the supported member. Like Swartz and Kulpa, to allow relative movement between the fixed bracket and the slide clip, Sharp and Eldenburg taught that the fixed bracket should have an engaging component received by the portion of the slide clip lying against the supported member that is thicker than the receiving portion of the slide clip. Also, like Swartz and Kulpa, they taught that a planar securing component which is attached to the engaging component extended in parallel relation over the receiving portion of the slide clip. In Sharp and Eldenburg, their spacer or fixed bracket was a plate having a thickness that was greater than the portion of the slide clip that received it, thus the securing component that projected only outwardly from the top of the engaging component would not interfere with the movement of the slide clip in the plane of the supporting member but keep it from pulling away.
Patents with similar teachings include U.S. Pat. No. 6,213,679, issued in 2001 to Frobosilo and Viola, and U.S. Pat. No. 5,906,080, issued in 1999 to DiGirolamo and Mountcastle.
The slide clip of the present invention provides a uniquely shaped slide clip that is not prone to buckling under load.